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D McIntosh

Publications and source records attributed to D McIntosh.

11 recordsLinked to original sources
PubMed1992

Interactions between marine bacteria and dissolved-phase and beached hydrocarbons after the Exxon Valdez oil spill.

Turnover times for toluene in Resurrection Bay after the Exxon Valdez grounding were determined to be decades, longer than expected considering that dissolved hydrocarbons were anticipated to drift with the current and stimulate development of additional hydrocarbon-utilizing capacity among the microflora in that downcurrent location. These turnover times were based on the recovery of 14CO2 from added [14C]toluene that was oxidized. The concentrations of toluene there, 0.1 to 0.2 microgram/liter, were similar to prespill values. Oxidation rates appeared to be enhanced upstream near islands in the wake of the wind-blown slick, and even more within the slick itself. Specific affinities of the water column bacteria for toluene were computed with the help of biomass data, as measured by high-resolution flow cytometry. They were a very low 0.3 to 3 liters/g of cells.h-1, indicating limited capacity to utilize this hydrocarbon. Since current-driven mixing rates exceeded those of oxidation, dissolved spill components such as toluene should enter the world-ocean pool of hydrocarbons rather than biooxidize in place. Some of the floating oil slick washed ashore and permeated a coarse gravel beach. A bacterial biomass of 2 to 14 mg/kg appeared in apparent response to the new carbon and energy source. This biomass was computed from that of the organisms and associated naphthalene oxidation activity washed from the gravel compared with the original suspension. These sediment organisms were very small at approximately 0.06 microns 3 in volume, low in DNA at approximately 5.5 g per cell, and unlike the aquatic bacteria obtained by enrichment culture but quite similar to the oligobacteria in the water column.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Occupational↗
PubMed1992

Postoperative respiratory function after laparoscopic cholecystectomy.

Open cholecystectomy causes changes in pulmonary function test volumes; such changes can be related to respiratory complications of hypoxemia and atelectasis. Little data is available on lung volume changes after laparoscopic cholecystectomy. We measured preoperative and postoperative vital capacity (VC), functional residual capacity (FRC), arterial PO2, and chest X-ray atelectasis in 31 patients undergoing laparoscopic cholecystectomy and found small but significant decreases (p < 0.01) in VC (13 +/- 19%) and FRC (7 +/- 17%). The PO2 decreased from 89 +/- 11 mm Hg to 82 +/- 14 mm Hg, with only one patient's PO2 less than 60 mm Hg. Three patients demonstrated new segmental lobar collapse on postoperative chest X-ray. The postoperative changes in FRC (R2 = 0.40, p < 0.04) and atelectasis (R2 = 0.46, p < 0.03) could be predicted by multiple regression of risk factors, including obesity, smoking, use of narcotics, age, and symptoms of prior respiratory disease. We conclude that the respiratory changes after laparoscopic surgery are small in comparison to those expected after open cholecystectomy.

Cholecystectomy, Laparoscopic↗
PubMed1991

Effect of different doses of omeprazole on 24-hour oesophageal acid exposure in patients with gastro-oesophageal reflux.

To define the optimum doses of omeprazole appropriate for acute and long-term therapy of patients with gastro-oesophageal reflux disease, 24-h oesophageal pH was measured in 12 patients with symptomatic reflux and an abnormal 24-h oesophageal acid exposure time (greater than 6%) in a randomized, double-blind, four-way crossover study comparing the effects of omeprazole 10, 20, or 40 mg/day and placebo. Total reflux time over 24 hours, number of reflux episodes per hour, and the number of reflux episodes lasting greater than 5 minutes were measured by ambulatory 24-h oesophageal pH monitoring. All doses of omeprazole were superior to placebo in decreasing gastro-oesophageal reflux as measured by each index. With placebo, oesophageal acid exposure was 16.3% of the 24 hours, 10 mg omeprazole/day reduced that to 6.3%, 20 mg/day lowered acid exposure to 0.9%, and 40 mg/day to 0.6%. Thus only the 20 and 40 mg doses reduced acid exposure to within the normal range. Similar results were obtained with the other indices of reflux. These data suggest that a rational dose regimen for reflux oesophagitis is 20 mg/day, a regimen that has proved effective in clinical trials. The present study indicates that 24-hour oesophageal pH monitoring is a practical approach to the determination of drug dosage in patients with gastro-oesophageal reflux.

Adult↗
PubMed1991

Supportive therapy: the other therapy.

Nurses have a long history of caring for clients with chronic mental illness. A primary treatment modality used with these clients is supportive psychotherapy. Often this approach is not well understood, even by those who purport to practice it. While supportive therapy tends not to enjoy the prestige associated with other forms of individual psychotherapy, the author contends that supportive psychotherapy can be an interesting and challenging treatment modality for working with clients with chronic mental illness.

Chronic Disease↗
PubMed1978

Thyroid function after surgical treatment of thyrotoxicosis. A report of 100 cases treated with propranolol before operation.

We assessed thyroid function for 12 months after subtotal thyroidectomy in 100 tyrotoxic patients treated with propranolol alone before and immediately after operation. The operation proved safe, with low morbidity. Suppression of the hypothalamic-pituitary-thyroid axis, present in the majority one month after operation, was evidenced by normal or low levels of serum total tri-iodothyronine and thyroxine, but absent or subnormal serum thyrotropin response to thyrotropin-releasing hormone. Eighty patients were euthyroid at 12 months. Three patterns of thyroid function were observed in this group between the first and 12th months: normal serum total tri-iodothyronine, thyroxine and thyrotropin levels at all stages (20 patients); normal serum total tri-iodothyronine and thyroxine, but raised thyrotropin levels on one or more occasions (40 patients); and temporary hypothyroidism (20 patients). Of the remaining 20 patients, permanent hypothyroidism developed in 14, and six relapsed. Postoperative thyroid function was related to the estimated weight of the thyroid remnant.

Adult↗
PubMed1978

Thyroid tumor.

Explore the source record for details and available documents.

Adult↗
PubMed1976

Temporary hypothyroidism after surgical treatment of thyrotoxicosis.

Mild clinical hypothyroidism associated with low levels of serum total thyroxine (T4) and tri-iodothyronine (T3) and raised levels of serum thyroid-stimulating hormone (T.S.H.) has been observed in 14 of 40 patients (35%) in the early months after a subtotal thyroidectomy for thyrotoxicosis under cover of propranolol. In 10 of the patients, however, the hypothyroidism was temporary and at 6 months after operation the thyroid hormone levels were normal and the serum T.S.H. levels had fallen. In 4 of the patients in whom clinical and biochemical evidence of hypothyroidism persisted 6 months postoperatively, long-term T4 replacement therapy was instituted. It is concluded that the diagnosis of permanent hypothyroidism should not be made with confidence before 6 months have elapsed after operation and that the incidence of hypothyroidism following the surgical treatment of thyrotoxicosis may have been overestimated in the past.

Adult↗
PubMed1976

Propranolol in the treatment of thyrotoxicosis by subtotal thyroidectomy.

Subtotal thyroidectomy was performed in 40 patients with thyrotoxicosis in whom propranolol alone was used as preparation for surgery. Propranolol was given orally in a dose of 40 mg every 6 h for a mean preoperative period of 17 days (range 4-60 days) and continued for seven days after operation. The mean +/- SE blood loss at operation was only 160 +/- 20 ml. The period of follow-up was from three to nine months. Recurrent thyrotoxicosis has not occurred in any patient. Low levels of total serum triiodothyronine (T3) and total serum thyroxine (T4) were observed in the early postoperative weeks in some patients and were associated with symptoms of mild hypothyroidism, but by six months in the presence of a raised serum thyrotropin (TSH) the thyroid hormone levels returned to normal. Permanent hypothyroidism developed in only two patients. Despite normal or low total serum T3 and T4 levels, the TSH response to thyrotropin-releasing hormone (TRH) was absent in all patients one week after operation. At four weeks and at eight weeks, the response was absent or sub-normal in 70% and 20% of the patients respectively, indicating a delay in the recovery of the hypothalamo-pituitary axis previously exposed to high levels of T3 and T4. It is considered that subtotal thyroidectomy for thyrotoxicosis in patients prepared with propranolol is an acceptable procedure which has some advantages over the conventional preparation with carbimazole and potassium iodide, not the least of which are the potential reduction in preparation time, the more flexible timing of operation, and the reduced operative blood loss.

Female↗